Interest is how banks pay you to keep money in a savings account

A savings account makes money through interest—a percentage of your balance that the bank pays you each month or year. The bank uses your deposited money to lend to other customers and invests it; they share a portion of what they earn with you as interest. The amount you earn depends on three things: how much you have saved, the interest rate the bank offers, and how long the money sits in the account.

The interest rate varies widely. A high-yield savings account at an online bank might pay 4% to 5% annually, while a traditional brick-and-mortar bank might pay 0.01% or less. The difference is real: on $10,000, you'd earn roughly $400 to $500 per year at a high-yield rate versus $1 at a traditional bank. Rates change based on what the Federal Reserve does with its benchmark rate, so what you earn today may shift in a few months.

You don't have to do anything to earn this interest—it accrues automatically. The bank calculates it daily or monthly and deposits it into your account. You can then withdraw it or let it sit and earn interest on the interest (called compounding).

Key Takeaways

  • High-yield savings accounts at online banks currently pay 4% to 5% annually, while traditional banks often pay under 0.1%, making account choice the biggest factor in what you earn.
  • Interest rates are set by the bank and change when the Federal Reserve adjusts its benchmark rate, so your earnings will fluctuate over time.
  • Interest compounds—meaning you earn interest on your interest—if you leave the money untouched, which accelerates growth on larger balances.
  • You earn nothing on money you withdraw, so keeping funds in the account longer increases total interest paid to you.
  • Money market accounts and certificates of deposit (CDs) offer higher rates than savings accounts but come with withdrawal restrictions or lock-in periods.

How to compare interest rates across different banks

The first step is checking what rate your current bank offers. Log into your account online or call the customer service number on your card. The rate is usually listed under "Account Details" or "Interest Information." Write it down—most banks don't advertise their own rates prominently.

Then compare it to what other banks offer. Visit the websites of online banks like Marcus, Ally, American Express Personal Savings, or Discover. Each lists their current rate on the savings account page. You'll see the rate changes frequently (sometimes weekly), so check multiple banks on the same day to compare fairly. A difference of even 1% compounds significantly over a year.

Some banks offer promotional rates for new customers—a higher rate for the first few months. Read the fine print: these rates often drop to a standard rate after 3 to 12 months. Factor in what the standard rate will be, not just the promotional offer.

Moving money to a higher-rate account

If your current bank pays very little interest, moving your savings to a high-yield account is straightforward. Open an account at the new bank—this takes 10 to 15 minutes online. You'll need your Social Security number, a government ID, and proof of address (a recent utility bill or bank statement works).

Once the account is open, transfer your money from your old bank. Most banks let you link external accounts and move money electronically; this usually takes 1 to 3 business days. Some banks offer a transfer service where they handle the move for you. You can also withdraw cash and deposit it, though this is slower and riskier.

Close your old account once the transfer is complete, or leave it open if it has no monthly fee and you want a backup account. Closing is optional—there's no penalty for having multiple savings accounts at different banks.

Understanding compounding and how it increases your earnings

Compounding means the bank pays interest on your interest. Here's how it works: if you have $10,000 earning 5% annually, after one year you have $10,500. In year two, the bank calculates 5% on $10,500, not the original $10,000, so you earn $525 instead of $500. The extra $25 came from interest on your interest.

The longer money sits untouched, the more compounding helps. On $10,000 at 5% annually, after 10 years you'd have roughly $16,289 if you never withdraw. If you withdraw the interest each year, you'd have only $15,000. The difference grows larger with bigger balances and longer time periods.

Most savings accounts compound monthly or daily. Daily compounding is slightly better because interest accrues more frequently, but the difference is small. What matters far more is the interest rate itself and how long you leave the money alone.

Money market accounts and CDs as alternatives to savings accounts

A money market account is a hybrid between a savings account and a checking account. It typically pays a higher interest rate than a regular savings account (sometimes 1% to 2% higher) but may require a larger minimum balance—often $2,500 to $10,000. Some money market accounts let you write checks or use a debit card, though there are limits on how many times per month you can withdraw.

A certificate of deposit (CD) pays a fixed interest rate for a set period—usually 3 months to 5 years. The longer the term, the higher the rate. A 5-year CD might pay 5% while a 3-month CD pays 4%. The catch: you can't touch the money without a penalty. If you withdraw early, the bank charges a fee that eats into your interest. CDs make sense if you know you won't need the money for a specific time period.

For most people, a high-yield savings account is the best choice because it offers competitive rates without locking your money away. Use a money market account if you need occasional access and can meet the minimum balance. Use a CD only if you're certain you won't need the funds before the term ends.

What reduces or eliminates the interest you earn

Monthly fees are the biggest threat to your interest earnings. Some banks charge $5 to $15 per month for account maintenance, overdraft fees, or inactivity fees. On a $5,000 balance earning 5% annually, a $10 monthly fee wipes out nearly 2.4% of your earnings. Always check the fee schedule before opening an account. Most online banks charge no monthly fees.

Withdrawals don't directly reduce interest, but they do reduce your balance, which means less money earning interest going forward. If you withdraw $2,000 from a $10,000 account, you're now earning interest on $8,000 instead. This is why keeping money in the account longer increases total earnings.

Inflation also reduces what your interest earnings are worth in real terms. If inflation is 3% and your savings account pays 4%, your money is only growing 1% in purchasing power. This is why savings accounts are for short-term goals (under 5 years) or emergency funds. For longer-term growth, other investments like index funds may outpace inflation more reliably.

Calculating what you'll actually earn over time

Use this straightforward formula to estimate your earnings: (Balance × Annual Interest Rate) ÷ 12 = Monthly Interest. On $10,000 at 5%, that's ($10,000 × 0.05) ÷ 12 = $41.67 per month, or about $500 per year.

For a more precise calculation that accounts for compounding, most banks provide an online calculator on their website. Enter your balance, the interest rate, and how many months or years you plan to keep the money. The calculator shows you the final amount and total interest earned.

Keep in mind that rates change. If the Federal Reserve raises rates, your earnings will increase; if it lowers rates, your earnings will decrease. Check your bank's rate quarterly to see if it's still competitive. If it drops significantly, you can move your money to a bank with a higher rate.

Frequently Asked Questions

Do I have to pay taxes on savings account interest?

Yes. Interest earned is taxable income. Your bank will send you a 1099-INT form each January if you earned $10 or more in interest during the year. You report this on your tax return. The amount is usually small, but it counts as income.

What's the difference between APY and APR on a savings account?

APY (Annual Percentage Yield) is what banks use for savings accounts and includes compounding. APR (Annual Percentage Rate) is used for loans and doesn't include compounding. When comparing savings accounts, look at the APY—that's your actual earnings rate.

Can I lose money in a savings account?

No. Your balance is protected by FDIC insurance up to $250,000 per account at each bank. You won't earn much interest, but you won't lose your principal. The only way to lose money is if you withdraw more than you have or incur fees that exceed your interest.

Is it better to have one large savings account or split money across multiple banks?

Splitting across multiple banks doesn't earn you more interest—the rate is the same whether you have $5,000 in one account or $2,500 in two. The main reason to split is FDIC protection: each account at each bank is insured separately up to $250,000, so if you have $500,000 to save, you'd split it across two banks to stay fully protected.

How often does the interest rate change?

Banks can change rates whenever they want, though most follow the Federal Reserve's decisions. The Fed typically meets eight times per year. When the Fed raises or lowers its benchmark rate, banks usually adjust their savings rates within days or weeks. Check your bank's rate monthly if you want to stay on top of changes.